Conventional user input devices, such as joysticks, levers, knobs and buttons, typically include user interface structures that are manipulated and displaced by users. Some of these user input devices may require a mechanism to return the user interface structure back to its initial vertical position when the user interface structure is released by a user. Other user input devices may require a mechanism to return the user interface structure back to its lateral or horizontal position when the user interface structure is released.
The most common mechanism used to return a user interface structure of a user input device back to its initial vertical and/or lateral position is a coil spring. When a coil spring is released after being compressed, the coil spring will return to its resting length. Thus, a coil spring positioned below a user interface structure of a user input device can be used to return the user interface structure back to its initial vertical position. Furthermore, if one end of the coil spring is anchored, when the other end of the coil spring is released after being laterally displaced, the free end of the coil spring will return to its initial lateral position. Thus, the coil spring can be used to return the user interface structure back to its initial lateral position.
Since coil springs need to be anchored to function as self-centering mechanisms, the coil springs require additional components to anchor the coil springs to the user input devices. In addition, these additional components and the coil springs may need to be aligned to function properly. Thus, the self-centering coil springs can cause difficulties in manufacturing and assembly of the user input devices.
In view of these disadvantages, there is a need for a user input device with a self-centering mechanism that is easy to manufacture and does not require additional components for anchoring.